Visiting Cancun? Here’s an Update on Seaweed Conditions

If you’re planning a beach vacation and are worried about the current seaweed conditions in Cancun and Riviera-Maya, here’s some background information, an update on the Cancun seaweed problem and the sargassum seaweed forecast for 2019 and 2020 in Mexico. There are also some suggestions for the best beaches for swimming.

September 2019 Update on Seaweed in Cancun, Playa del Carmen, Puerto Morelos, Isla Mujeres and Tulum: On June 7th, the Government of Quintana Roo declared a state of emergency due to the large amount of sargassum seaweed in certain municipalities. The seaweed problem continued until August 2019, when winds and ocean currents shifted and the sargassum seaweed disappeared from almost all beaches. However, satellite images show a large seaweed mat offshore in the Caribbean and it may hit Mexico’s coastline by the end of September.

Scroll down for an update on seaweed conditions right now and a sargasso seaweed map

Sargassum Seaweed Facts

What exactly is sargassum seaweed and why is it a problem? Sargassum is a type of brown algae that generally lies in the open ocean in the Sargasso Sea in the North Atlantic. Wrapped by ocean currents, this mat of seaweed floats on the surface of the water and serves as a resting area and spawning ground for a vast array of life from eels to sea turtles.

While sargassum seaweed is a natural phenomenon that has been occurring for centuries, the influx of sargassum in recent years have been larger, thicker and more widespread. Since 2011, blooms of sargassum have been appearing in the tropics sweeping up from South America through the Caribbean along the coast of Mexico and into the Gulf of Mexico and Florida. The summer of 2018 witnessed the worst influx of sargassum brown algae in recent history.

The quantity of the sargassum seaweed combined with differences in the composition of the seaweed itself, has been posing problems for destinations where vast quantities of seaweed are floating on the surface of the water, washing up on beaches, trapping marine life in the seaweed itself and using up the oxygen that fish need to breathe.

Various strategies — from raking it manually to using barriers to catch the sargassum before it reaches the shore — have been devised to try to deal with the unprecedented waves of seaweed that have engulfed regions of the Caribbean and Mexico in 2015, 2018 and 2019.

Is it Dangerous to Swim in Sargassum Seaweed?

Sargassum seaweed in itself doesn’t pose a problem, says Dr. Jeffrey Rapaport at Holy Name Hospital in Teaneck (Emeritus head of Dermatology). Instead, it’s what the seaweed harbours that can cause skin irritations and other risks.

The seaweed when floating at the top of hot, shallow waters, can start to play host to microbes and strains of bacteria the skin is not accustomed to coming in contact with. Also, you have to remember that fish normally use sargassum as a breeding grounds — leaving toxins and eggs in seaweed.

With freshwater as well as saltwater swimmers should watch out for the growth of Cyanobacteria (which can normally be seen changing the water’s colour to light green). Cyanobacteria can release neurotoxins, which not only can affect the skin but can cause the death of neurons that control most of the muscles and movements in your body.

In addition to being unsightly, there are potential risks to swimming in seaweed

Another risk occurs when sargassum seaweed gathers in large quantities, washes up on beaches and begins to decompose, releasing hydrogen sulfide gas, or H2S , a colourless, poisonous gas with an unpleasant rotten-egg odor,

According to an interview in the San Pedro Sun with Eric Najarro, Administrator at the Dr. Otto Rodriguez San Pedro Polyclinic II in Belize, inhaling small doses of the gas can trigger irritation of the eyes, respiratory issues and nausea, especially among at-risk people such as those with asthma, the elderly, infants and pregnant women. Certain animals, especially dogs, are also sensitive to the inhalation of hydrogen sulfide.

Another health risk to swimming with large quantities of sargassum seaweed is the potential for skin irritations and rashes.

Note that red tide and sargassum seaweed are two different problems. A red tide is a bloom of algae that discolours coastal waters and releases dangerous toxins. Eating shellfish or other seafood during an algal bloom is harmful to humans.

Seaweed Season in the Caribbean and Mexico

This was the scene earlier in Cancun during the summer of 2018

In the Caribbean, seaweed season is generally May to October. In 2018, the influx of sargassum seaweed hit its peak in the summer months. On June 7, the government of Barbados even declared a national emergency due to the enormous masses of sargasso on its beaches.

While some destinations such as Belize are still struggling with vast amounts of sargassum seaweed, the good news is that many of the beaches in the Caribbean never did experience a seaweed problem and others have seen a drastic reductions in the amount of seaweed in early 2019. However by mid 2019, this situation changed.

The popular resort town of Playa del Carmen has been experiencing a double whammy of challenges in recent years. From the erosion of its beaches to an influx of sargassum seaweed along the coast of Quintana Roo, it’s been working hard on developing strategies to cope with these issues which are posing an environmental problem and preventing people from enjoying the coast’s famous beaches.

Seaweed Conditions in Cancun 2018-2019

No sargassum at the Grand Fiesta Americana Coral Beach Cancun

The current seaweed conditions in Cancun, Mexico had been improved over what they were in the summer of 2018. The state of Quintana Roo received federal funding from the Natural Disasters Fund to help with the removal of the sargasso and that, has been combined with a reduction in the quantity of seaweed arriving on the beaches of Cancun and Riviera Maya.

I personally walked many of the beaches in Cancun in October and early November 2018 and noticed a significant reduction compared to previous months. While conditions do vary daily, during my inspections many beaches had no seaweed or there were just a few small clumps of seaweed in the water.

However, conditions can change at any time and predictions are that the seaweed may return.

Best Cancun Beaches Without Seaweed – Playa Caracol

Swimming is fine along this coast in front of Grand Fiesta Americana Coral Beach Cancun

This beach stretches along the northern shores of what’s known as Punta Cancun or the most northerly point of the Cancun Hotel Zone. There is a ferry to Isla Mujeres departing from the pier between the Riu and the Grand Fiesta Americana Coral Beach Cancun. The public beach has small amounts of seaweed but nothing that is bothersome.

Next door at the Grand Fiesta Americana Coral Beach Cancun Resort & Spa, the private beach is often completely clear of sargassum and features powder soft white sands and clear turquoise waters. It is usually protected from seaweed by nearby Isla Mujeres, however wind and ocean currents can change and seaweed conditions at Grand Fiesta Americana Coral Beach Cancun can change quickly. SCROLL DOWN TO SEE THE LATEST MAP OF SEAWEED CONDITIONS IN 2019.

An advantage of Coral Beach is that the waters are calm and the entry is gradual with no steep drop-off, making it ideal for those who aren’t expert swimmers.

In my opinion, this is the best beach in Cancun for swimming. Beginner swimmers, small children and seniors will all enjoy swimming at this beautiful beach.

One of the most popular public beaches in Cancun, Playa Gaviotas Azul is located at the northern tip of the hotel zone. Beach access is between Coco Bongo and the Mandala Beach Club opposite Hooters via a narrow alleyway. Current seaweed conditions at Playa Gaviota Azul are much improved from what they were in the summer and even in early October.

During the first week of November 2018, any small clumps of seaweed on the sand were being raked up by hotel staff . There was very little sargassum seaweed floating offshore. The major hotels on these beaches include the all-inclusive Krystal Cancun and the Hyatt Ziva Cancun at the point of the peninsula.

However wind and ocean currents can change and seaweed conditions can change quickly. SCROLL DOWN TO SEE THE LATEST MAP OF SEAWEED CONDITIONS in CANCUN in 2019.

Best Cancun Beaches Without Seaweed – Playa Delfines / Dolphins Beach

No invasion of seaweed on this beach in November 2018!

This long, wide public beach at the southern end of the Hotel Zone is known as Playa Defines and is one of the most popular beaches in Cancun. You’ll also see line-ups of people waiting to get a photo-op in front of the CANCUN sign.

The amount of seaweed on Playa Delfines has decreased in early 2019. See below for a photo of what it looked like in 2018.

You can see the sargassum seaweed gathering offshore in this shot from August 2018

However wind and ocean currents can change and seaweed conditions can change quickly. SCROLL DOWN TO SEE THE LATEST MAP OF SEAWEED CONDITIONS in CANCUN in 2019.

Current Cancun Seaweed Conditions – Sargassum Forecast 2019

The original sargassum forecast predicted that the quantity of seaweed in Cancun and Riviera-Maya would reach its peak in July and August 2018. It was then projected to disappear by December 2018 and the beaches were in fact back to their natural state of turquoise waters and powder white sand by the peak holiday season.

The forecast for seaweed season in 2019 is not encouraging. A report by Brigitta Ine van Tussenbroek, an ocean researcher from the Institute of Marine Sciences and Limnology at the National Autonomous University (UNAM) suggests that large quantities of sargassum seaweed are likely to return to Quintana Roo and the beaches of Mexico’s Caribbean coast in 2019.

Recent satellite images also show large floating masses of seaweed in the Atlantic between southern Africa and Brazil. Whether it will land in Cancun, Chetumal or the Riviera Maya is unclear as much depends upon atmospheric conditions such as trade winds.

Current Seaweed Conditions in Playa del Carmen and Tulum – 2019 and 2020

June – August 2019 Update: In June and July 2019, unfortunately, satellite and reports in local media in Mexico indicate that critical masses of sargassum seaweed mats began to land on the beaches of Quintana Roo. On July 7th, The government of Quintana Roo issued an emergency declaration for the coasts of the municipalities of Lázaro Cárdenas, Isla Mujeres, Benito Juárez, Puerto Morelos, Cozumel, Solidaridad, Tulum, Felipe Carrillo Puerto, Bacalar and Othón P. Blanco.

Declaring a State of Emergency enables local authorities to access funding to combat the volume of seaweed by removing accumulations and blocking it by various methods.

By early August, the winds and currents shifted so the sargasso seaweed mats were no longer landing on the beaches of Quintana Roo. This is great news as it means the sargasso problem has disappeared from most beaches in Cancun and Riviera Maya.

It’s important to note that Cancun seaweed conditions can change daily depending on tides and water temperature. To continue to monitor current seaweed conditions throughout the Caribbean, Mexico and the Gulf of Mexico, there are several options.

Sargassum Seaweed Tracker

You can check the Sargassum Early Advisory System (SEAS), a forecasting project based in Texas intended to help predict the movement of sargassum blooms. Originally created in 2013 to help with forecasting of the large Sargassum landings in Texas, by 2017 the SEAS project had expanded to provide forecasting for the Gulf Coast, Mexico, Grand Cayman, Jamaica, Haiti, Saba, the Dominican Republic, Puerto Rico and many other Caribbean islands.

The SARGASSUM EARLY ADVISORY SYSTEM provides forecasts of sargassum in the Caribbean

The SARGASSUM EARLY ADVISORY SYSTEM can forecast sargassum seaweed masses up to eight days in advance.

Get Maps, Updates and a Seaweed Report on Facebook – Red de Monitoreo del Sargazo

This not-for-profit group is made up of engineers, biologists and other experts who are volunteering their time to provide monitoring expertise and services. They published this map of areas affected by sargasso seaweed in Cancun, Riviera Maya and Tulum on Sptember 5, 2019. Get updates from the Red de Monitoreo del Sargazo Cancun Facebook Page.

Dividing her time between Toronto, Mexico and Guatemala (or the nearest tropical beach), Michele Peterson is an award-winning writer, blogger, editor and publisher who specializes in travel, cuisine and luxury lifestyles.

Thanks for the information, Michelle! I know red tide has been a big problem on the Gulf Coast of Florida this year, so whenever we are traveling to a coastal area, it’s a good idea to check the current local conditions…

It really depends where in Playa del Carmen you are going…there is a fair bit of beach erosion in front of some resorts which makes it hard to dodge seaweed when there’s an influx. Today there is some mucky accumulation while other stretches are fairly clear. That having been said, New Year’s Day in front of Kool Beach Club and Mamitas there was quite a bit of seaweed but not overwhelming. People were still swimming in the sea. It’s hard to predict the situation in March….but you can check out the current conditions via a beach cam at this link https://www.playadelcarmen.com/information/webcam

We’ve been at Catalonia Playa Maroma this week and the water looks like sewage. We had six days of brownish water which we were able to swim in and enjoy, but it was really bad today. Yikes. Hope they can get it under control. It’s beautiful here.

Thank you for the information. We were there in June 2018 and, as other have said, The beaches are perky, full of the sea grass, with an offense of order. We’re hoping to return and fall of this year. Any advice?

Hi Sara…sorry to hear you had such a unpleasant experience last June! The good news is that generally the fall season sees less seaweed than summer. I was at Coral Beach in Cancun in late 2018 and there was no seaweed for the duration of my stay. It’s difficult to predict as much depends on winds and ocean currents as well as where on the coast you are headed. I’ll post any updates as I get them so please do check back!

It’s very difficult to predict seaweed conditions so far in advance. But generally speaking April isn’t the height of seaweed season so that’s a promising sign. It’s worth checking on the resources I’ve listed and register for updates from the Grupo de Red de Minitoreo de Cancun on Facebook ( https://www.facebook.com/groups/2272972109391283/) as they publish maps and forecasts for the coast of Mexico. Grand Velas is a beautiful resort with lots to do so even if you do get some seaweed it’s a lovely place to be.

Thank you so much for sharing this article! It is so helpful to see and understand the reason of this phenomenon. We are planning a family reunion for July 2020 in Playa del Carmen. However, by reading this article I learned of other options to stay at. I will keep a close look at the forecast and accumulation. Thank you!

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About Michele

Dividing her time between Canada, Mexico and Guatemala, Michele Peterson's work has appeared in Lonely Planet’s cookbook Mexico: From the Source , National Geographic Traveler, Fodor's, WestJet and more than 100 other publications.

Here at A Taste for Travel she travels the world scouting out the most fascinating food experiences to help readers plan their own vacations or create recipes at home. Her writing has been recognized with awards by the Caribbean Tourism Organization (CTO), the North American Travel Journalists Association (NATJA) and Destination Ontario.